(adj.adj.) : Tartărus or -os, i, m., in plur. (on prosodial grounds): Tartăra, ōrum, n., = Τάρταρος, plur. Τάρταρα
* The infernal regions, Tartarus (poet.; in prose, inferi); sing., Lucr. 3, 1012; Verg. A. 6, 577; Hor. C. 3, 7, 17; Stat. S. 2, 7, 116; plur., Lucr. 3, 42; 3, 966; 5, 1126; Verg. A. 4, 243; 6, 135; Hor. C. 1, 28, 10; Ov. M. 1, 113; 5, 371; 5, 423; 10, 21 et saep. al.—Personified: Tartarus pater,i. e. Pluto,Val. Fl. 4, 258.—Hence
* Tartărĕus, a, um, adj., of or belonging to the infernal regions, Tartarean, infernal: tenebrica plaga, Cic. poët. Tusc. 2, 9, 22: antrum,i. e. the infernal regions,Luc. 6, 712: umbrae,Ov. M. 6, 676; 12, 257: custos,i. e. Cerberus,Verg. A. 6, 395: Acheron,id. ib. 6, 295: Phlegethon,id. ib. 6, 551: sorores,i. e. the Furies,id. ib. 7, 328; Stat. Th. 5, 66; hence, vox Alectus,Verg. A. 7, 514.
* Tartărĭnus, a, um, adj., Tartarean, infernal;poet. for horrid, terrible: Tartarino cum dixit Ennius, horrendo et terribili Verrius vult accipi, a Tartaro, qui locus apud inferos,Fest. p. 359 Müll.: corpore Tartarino prognata Paluda virago, Enn. ap. Varr. L. L. 7, 37 ib.—Trop.: delator,Amm. 15, 6, 1.

Tartărus (noun M) :
* A river of Italy, now Tariaro, Tac. H. 3, 9.